Impact of elevated air temperature and CO2 concentration on canopy photosynthesis and growth of soybean

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POSTER 17

216

-상승된 대기 온도 및 이산화탄소 농도가 콩의 생장 및 군락광합성에

미치는 영향

상완규

1_*

_{, 이윤호}

1

_{, 김준환}

1

_{, 신평}

1

_{, 백재경}

1

_{, 조정일}

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_{, 서명철}

1 1_{농촌진흥청 국립식량과학원}

Impact of elevated air temperature and CO

2

concentration on canopy

photosynthesis and growth of soybean

Wangyu Sang

1*

, Yunho Lee

1

, Junhwan Kim

1

, Pyeong Shin

1

, Jaekyeong Baek

1

, Jeongil Cho

1

and

Myungchul Seo1

1

Crop Physiology and Production, National Institute of Crop Science, Rural Development Administration, 181, Hyeoksin-ro, Iseo-myeon, Wanju-gun, Jeollabuk-do 55365, Republic of Korea

Global climate change is one of the biggest problems the world is facing now. Elevated air temperature and CO2 caused by global warming can affect the growth and productivity of most

crops. In this study, experiments were conducted to evaluate the impacts of climate change on the canopy photosynthesis, growth, and seed yield of the determinate soybean cultivar in Southern Korea.

Both air temperature and CO2 did not affect the phenology of vegetative stage and were not

significantly related to the flowering time. Elevated temperature extended the R1-R5 period, while elevated CO2 extended the R5-R7 period.

Canopy photosynthesis and growth were strongly influenced by elevated air temperature and CO2

and also showed significant differences according to the growth stages. On vegetative stage, both of elevated air temperature and CO2 had positive effects on daily net photosynthetic rate and synergistic

effects on growth and development of soybean. On reproductive stage, elevated air temperature had negative physiological effects such as the abortion of flower and decreased photosynthetic ability. However, elevated CO2 relieved these negative effects induced by elevated air temperature.

Elevated temperature decreased pod and seed numbers. However, elevated CO2 compensated for

negative effects on pod and seed number by heat stress by creating more branches. Seed size tended to be more strongly affected by air temperature than CO2 concentration. Seed size had a strongly

negative relationship with elevated temperature during seed filling stage, whereas a weaker positive relationship with elevated CO2. Based on these results, we also revealed that elevated temperature

was a major factor in determining seed size rather than elevated CO2.

Therefore, considering the climate change at 2071~2100 years in southern Korea, it will be required strategies to avoid high temperature stress during reproductive stage, especially R5-R7 period

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POSTER 17

217 -for stable production of soybean.